def test_find(self):
dll = DoublyLinkedList()
dll.append('A')
dll.append('B')
dll.append('C')
assert dll.find(lambda item: item == 'B') == 'B'
assert dll.find(lambda item: item < 'B') == 'A'
assert dll.find(lambda item: item > 'B') == 'C'
assert dll.find(lambda item: item == 'D') is None
def test_find(self):
ll = DoublyLinkedList(['A', 'B', 'C'])
assert ll.find(lambda item: item == 'B') == 'B'
assert ll.find(lambda item: item < 'B') == 'A'
assert ll.find(lambda item: item > 'B') == 'C'
assert ll.find(lambda item: item == 'X') is None
def test_find(self):
dll = DoublyLinkedList(['A', 'B', 'C'])
assert dll.find(lambda item: item == 'B') == 'B' # Match equality
assert dll.find(lambda item: item < 'B') == 'A' # Match less than
assert dll.find(lambda item: item > 'B') == 'C' # Match greater than
assert dll.find(lambda item: item == 'X') is None # No matching item
